| 摘要 |
PROBLEM TO BE SOLVED: To provide a cold accumulating device usable to accumulate cold of a material having very low temperature <=-100 deg.C, having a large cold accumulating amount per unit mass, and using a cold accumulating agent having high heat transferring performance; a cold accumulating method of it; and a reliquefying method of BOG by the cold of LNG. SOLUTION: A first cold accumulating tank 4 capable of accumulating cold as sensible heat or latent heat of solidification in a pressure vessel in the temperature range <=-100 deg.C and filled with a first cold accumulating agent selected from a group of HFC-134a, HFC-23, HFC-32, ethane, propane, butane and pentane, and a second cold accumulating tank 7 capable of accumulating cold as sensible heat or latent heat of solidification in a pressure vessel in the temperature range of -100 deg.C to -50 deg.C and filled with a second cold accumulating agent of methanol, ethanol, a mixture of methanol and water a mixture of ethanol and water, or a mixture of methanol, ethanol and water are connected in series. LNG is allowed to flow the cold accumulating tanks in order, and cold is accumulated by heat exchanging through respective cold accumulating agents via partition walls to reliquefy BOG by making use of accumulated cold. |
